Light-extinguisher for arc-lamps



E. A. SPERRY.

LIGHT EXTINGUISHE'R FOR ARC LAMPS.

APPLICATION FILED MAY 5. 1916.

1,362,574, Patented Dec. 14, 1920.

2 SHEETS-SHEET I.

J/VVENTOR. E L MER H SPERRY.

ATTOR EY,

E. A. SPERRY.

LIGHT EXTINGUISHER FOR ARC LAMPS.

APPLICATION FILED MAY 5, I916.

Patented Dec. 14, 1920.

2 SHEETSSHEET 2- Y the closed position.

PATENT OFFICE.

ELHER SPERRY, F BROOKLYN, NEW YORK.-

LIGHTPEXTINGUISHER FOR ARC-LAMPS.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed llltay 5, 1916. Serial No. 95,724.

.To all whom, it may concern:

Be itknown that I ELMER A. SPnRRY, a citizen of the United States of America, residing at 1505 Albemarle road, Brooklyn, in the county of-Kings and State of New York,have invented certain new and useful Improvements in Light-Extinguishers for Arc-Lamps, of which the following is a specification.

electrode holders for searchlights,

-This' invention relates to a means for preventing the afterglow in arc lights which occurs when the current is switched off. In military and naval searchlights it is very important that means he provided whereby the light may be entirely extinguished on a moments -notice. power searchlights, especially in the type disclosed in my Patent No. 1,282,133 for issued October 22, 1918, the electrode tips will continue to glow for several minutes after the current is shut ofl', so that alight would -be visible to the enemy at a time when it is most desired that the light should he invisible. The object of this invention 1s to provide ,a simple, positive means, operable vertical longitudinal my invention applied thereto.

- are enlarged details.

automatically by the switching on and off I of the energizlng current for entirely inclosing the electrode tips and theportions of the Searchlight immediately adjacent thereto, which means are automatically re- ,moved to an inoperative position upon lighting ,of the lamp. to -the-drawings in whlch what Referring I now consider to be the preferred forms 2 of my invention are shown: Figure 1, is a section of a Searchlight,

showin Fig. 2 1s a plan View of the two part shield or light extinguishing means showing the parts in the closed positions. Figs. 3 and 4 Fig. 5 is a modification of the operating means for the shields. Fig. 6 is an elevation, partly in section, of

While my inventionis well adapted for any type ofv are light or Searchlight, it is especially adapted for the type of searchlight disclosed in my Patent No. 1,318,701

for method: of [Searchlight ventilation,

issued Oct. 14, 1919, and in patent. Accordingly this t shown in the drawings.

my aforesaid pe of light is he Searchlight drum is shown at 1 and the projector at 2.

In high the electrode holders showing the shield in' Fig. 2, to

the negative electrode 9 adjacent the arc,

the electrode being fed through the holder by means of rotary shaft 10. For strikingthe are, however, the entire holder and its support 11 are moved bodily away from the positive carbon. For this purpose the support 11 may be pivoted at 12. The solenoid 13, preferably in series with the arc, serves to rotate support 11 on. its pivot against the compression spring 14 within the sole- 'noid so as to strike the arc. My preferred form of light extinguisher comprises a pair of hollow members or shields 15, 16, each of which is pivoted and oscillated about an axis 116 by being secured respectively to legs 17, 18. Leg 17 is pinned or otherwise secured to a shaft 19 journaled in a bracket 20 upon support 4. Also secured to said shaft is a bevel pinion 21, which meshes with bevel gear 22 upon-a vertical shaft 23. Also meshing with said bevel gear is a second pinion 24 secured to a sleeve 24' surrounding shaft 19, the leg 18 being secured to said sleeve. It will thus be seen that by rotating shaft 23 the two hollow members 15, 16 will .be rotated in opposite direc= tions about axis 116, and will be thrown from the dotted line position to the full line position, or vice versa. Y i The legs 17 and 18 are preferably.provided with counterbalancing weights 25. It will be seen thatwhen the-shields are closed they entirely inclose a considerable portion of the electrode back of. the ti s and also'portions of the adjacent electrode holders which are likely to become red or white hot. The two halves of the shield preferably overlap or interfit, as shown on prevent any light escaping.

also prefer to equip the shield with a ventilating means, such as chimneys 26, preferably above and below the arc, so that a free circulation of air through the shield is permitted. The chimneys 26 are high enough to prevent any light from the electrodetips from reaching the projector. The shield is preferably so designed that in the open position, which is the full line position in Fig. 1, the cups are in line with what is termed the blind spot on the mirror. Tn other words, they are in line with the shadow caused by .the negative head upon the -mirror. As I prefer to position the negative carbon at an angle to the positive, this shadow lies, in the form shown, considerably below the positive head.

To operate the shield a connection from the shaft 23 to the negative holder is provided,'so that the shield may be operated by the striking of the arc. Preferably this con nection assumes the form of a pivoted rack bar'27, provided with teeth 28 facing said shaft, and meshing with a pinion 29 loosely mounted on the shaft. Said pinion is provided with a clutch face 30 for cooperation with the clutch tooth 31 on the member 32, slidably but non-rotatably mounted on said shaft. The tooth 31 is made much smaller than the corresponding depression 32 in the face 30 of pinion 29, so that the negative holder will be allowed to move back a predetermined distance before the shaft 23 is rotated. This renders the operation of the parts more reliable since the solenoid 13 is given an opportunity thereby to place the negative head in motion before it is compelled to move the shields. j

A finger piece 33 may also be provided on clutch member 32 whereby the clutch mem-' ber may be moved back out of contact with the pinion, and the shaft 23 rotated by hand opening the shields and will insure a limited amount of lost movement occurring before the motion of the are striking mechanism will positively open the shields. I

In the modification shown in Fig. 5, the shields'15 and 16 instead of being pivoted adjacent the arc are pivoted at p0ints116 and 116 near the circumference of the drum. The two parts of the shields are mounted on long curved arms 40, 41 which I are secured adjacent their upper ends to intermeshing gear sectors 42, '43, pivoted at said points 116 and116". It will readily be seen that by rotating one sector as by means of a handle 44 the shield may be opened and closed at will. If desired a solenoid 45 adapted to be placed in the arc circuit may be provided-to operate the derecast/4- vice automatically in a similar fashion to the operation of the preferred form of the invention.

It will be seen that when the holders are open that although they still lie within the searchlight drum they lie beyond the peripheryof the mirror and therefore. lie wholly without the searehlight beam.

The operation of my device is very simple. When the lamp is out the shield is normally closed, as shown in Fig. 2. or on dotted lines in Fig. 1. As soon as the are cur rent is turned on and the arc strikes. the mechanism will open the shields. placing them where they will intercept little or no light from the mirror. If it is desired to extinguish the light quickly. all that need be done is to turn off the main supply current and the are striking mechanism will cause the negative head to again move toward the positive and thereby quickly close the shields around the white hot tips of the electrodes and adjacent portions ofthe holders.

In accordance with the provisions of the patent statutes, 1 have herein described the principle of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use. 1

Having described my invention, what I claim and desire to secure by Letters Patent is l. The combination with are light electrodes, of a light shield therefor and means for causing said shield to assume the operative position when the current through the electrodes is substantially zero.

2. The combination with arc light electrodes, of a light shield adapted to inclose the electrode tips and means for causing said shield to assume the operative position when the current through the electrodes is substantially zero.

3. In combination, are light electrodes. means for preventing afterglow when the arc is cut out and means for operating said first mentioned means when an arc producing current is passed through the electrodes.

4. The combination with are light electrodes, of a light shield therefor, and means responsive to the closing of the arc circuit for moving said shield to an inoperative position.

5. In an are light, the combination with the electrodes-and electrode holders and an are striking mechanism therefor, of a light 7. In an are light, the combination with the electrodes and electrode holders and an are striking mechanism therefor, of a light shield for concealing the after glow comprising a pair of pivoted members adapted to normally inclose the electrode tips and mechanism brought into operation by a predetermined portion, only, of the movement of said are striking mechanism for moving said members to an inoperative position.

8.'In an are light, the combination with the electrodes and electrode holders therefor, of a light shield for concealing the after glow comprising a pair of members each pivoted to one side of the line connecting the electrode tips and each movable toward and away from the latter.

9. In an are light, the combination with the electrodes and electrode holders therefor, of a light shield for extinguishing the after glow comprising a pair of pivoted members adapted to normally inclose the electrode tips from opposite sides said members being provided with ventilating means.

10. In an are light, the combination with.

electrodes and electrode holders, of a light shield for concealing the afterglow comprising a plurality of pivoted members, an are striking device and means including a lost motion connection between said device and pivoted members for operating the latter.

11. In combination, an are light, means for concealing afterglow thereof and means including an electro-magnetic device in se ries with the are for causing the operation of said first mentioned means.

12. A removable shield for concealing the after-glow of an arc lamp, comprising a plurality of members pivotally mounted for oscillation about a common axisand means for causing said members to approach each other to form an arc-inelosing screen which completely incloses the are tips.

13. An after-glow preventing screen for are lamps comprising a'plurality of hollowed out members coupled to each other for simultaneous but opposite movement about an axis at a distance from said members, and means for separating said parts from each other.

14:. An after-glow preventing screen for are lamps comprising an electrode holder, a plurality of screen members pivotally mounted thereon about an axis, a plurality of gears mountedfor oscillation about said axis, a connection between each screen mem* her and a corresponding gear and means for simultaneously oscillating said gears in opposite directions. a

15. In an are light, in combination, a movable electrode holder and means for concealing afterglow operatively connected to said holder, whereby said means is ren- 'dered operative on extinguishing the arc.

16. In an arc lamp, a plurality of electrode holders, means for moving one of the holders away from another holder to strike the are, a shield for concealing afterglow and a connection between said one of the holders and the shield for moving the latter to inoperative position when the arc is struck. A v

17. In an arc lamp, electrodes, a pluralityof electrode holders therefor, one of which, is fixed, means for moving one of said holders to strike the are, a multi-part shield adapted to inclose the electrode tips and connections between said movable holder and said shield for separating the parts of the latter when the arc is struck.

18. In an arc lamp, an electrode holder, means for moving said'holder to strike the are, a shield comprising a plurality of parts pivoted for oscillation about a common axis a gear wheel operatively connected to all 0 said parts and operative connections between said gear wheel and said holder.

19. In an are light in combination, an electrode holder movable toward and away from the arcing position, and means brought into operation by the last named movement of said holder for concealing the afterglow.

In testimony whereof I 'have aifixedmy signature.

ELMER A. sPERRY. 

